Food security in a water-scarce world:making virtual water compatible with crop water use and food trade

Virtual water has been proposed as a mechanism with potential to reduce the effects of water scarcity on food security. To evaluate the role of virtual water in reducing the effect of water scarcity on food security, all components of the available water resource in agricultural areas must be quantified to provide a basis for evaluating food imports driven by water scarcity. We refer to this situation as ‘agri-compatible connections’ among water scarcity, virtual water, and food security. To date, this has not been captured in the literature on water scarcity, virtual water flows and food security. The lack of agri-compatibility has rendered the virtual water concept seemingly inconsistent with trade theories and water-food security policy needs. We propose two requirements for achieving agri-compatible connections: (i) the limit of crop production imposed by water scarcity should be captured by quantifying all components of the water available to satisfy specific crop water requirement in the importing economy, and (ii) food import should satisfy ‘water-dependent food security’ need, which is the actual or potential food security gap created by insufficient available water from all sources for crop production (all other things being equal). Further, we propose that agri-compatible water scarcity should capture three key elements: (i) a reflection of aridity or drought potential, (ii) quantification of all the components of water resource available to a given crop at a given locality and time, and (iii) use of crop- and catchment-specific water scarcity factors to evaluate the effect of crop production and virtual water on water scarcity. In this paper, we show the conceptual outlines for the proposed agri-compatible connections. Achieving agri-compatible connections among water scarcity, virtual water and food security will enhance the analysis and understanding of the role of virtual water for food security in the importing economy and water scarcity in the exporting economy. We suggest that achieving agri-compatibility will improve the use of virtual water as a mechanism to reduce existing and future pressures on global food securit

Simulated Regional Yields of Spring Barley in the United Kingdom under Projected Climate Change

This paper assessed the effect of projected climate change on the grain yield of barley in fourteen administrative regions in the United Kingdom (UK). Climate data for the 2030s, 2040s and 2050s for the high emission scenario (HES), medium emissions scenario (MES) and low emissions scenario (LES) were obtained from the UK Climate Projections 2009 (UKCP09) using the Weather Generator. Simulations were performed using the AquaCrop model and statistics of simulated future yields and baseline yields were compared. The results show that climate change could be beneficial to UK barley production. For all emissions scenarios and regions, differences between the simulated average future yields (2030s–2050s) and the observed yields in the baseline period (1961–1990) ranged from 1.4 to 4 tons·ha−1. The largest increase in yields and yield variability occurred under the HES in the 2050s. Absolute increases in yields over baseline yields were substantially greater in the western half of the UK than in the eastern regions but marginally from south to north. These increases notwithstanding, yield reductions were observed for some individual years due to saturated soil conditions (most common in Wales, Northern Ireland and South-West Scotland). These suggest risks of yield penalties in any growing season in the future, a situation that should be considered for planning adaptation and risk management

Ghanaians Might Be at Risk of Inadequate Dietary Intake of Potassium

Adequate dietary intake of potassium (K) helps fight noncommunicable diseases (NCDs), mainly hypertension and cardiovascular diseases. This paper (i) estimated the K intake of Ghanaian population using food supply and food composition data and (ii) compared this estimate with the WHO recommended requirement for K in order to assess if there is a risk of inadequate K intake. Food supply data (1961–2011) was obtained from the FAO Food Balance Sheet (FBS) to derive trends in food and K supply. The average food supply in the FBS for 2010 and 2011 was used in assessing the risk of inadequate dietary intake of K. The K contents of the food items were obtained from food composition databases. The mean K supply per capita per day was approximately 856 mg. The assessment suggests a potentially large risk of inadequate dietary K supply at both individual and population levels. The results suggest the need for assessing options for managing K deficiency, including assessment of K supplying power of soils and K fertilizer management in food crop production systems, as well as empirical estimates of K content of food items (including those underreported in the FBS) and mixed diets in Ghana

A Meta-Analysis of Modifications of Root System Traits of Crop Plants to Potassium (K) Deprivation

Unlike nitrogen (N) and phosphorus (P), morphological responses of root systems of crop plants to potassium (K) dynamics in soils or growth media are only gaining currency. This is due to the realization of the instrumental role of K in several cellular and tissue level processes crucial for the growth, stress tolerance, metabolic functions, and yield of crop plants, and ultimately, food security and sustainable agriculture. This chapter used meta-analysis to synthesize the pooled evidence for modifications in several root system traits of different crop plants under conditions of K starvation in different growth media. In all, 37 studies that passed inclusion/exclusion criteria, from 1969 to 2019, were analyzed in aggregate and then disaggregated for root biomass, root length, and the number of roots. Three moderators were analyzed: type of soil or growth medium, crop, and K fertilizer applied in the included studies. The aggregated results show that the cumulative effect of K deprivation was a significant and large reduction (about 25.5 ± 15.0%) in the bulk of root system traits considered, which was slightly lower than the reduction in shoot- or yield-related traits. Reductions of approximately 38 ± 38.0% in root biomass and 23.2 ± 18.6% in root length were observed, and the magnitudes of reduction were comparable to those observed from the disaggregated data. Though reductions in root system traits due to K starvation occurred under both greenhouse/lab and field conditions, the cumulative reduction in the former was significantly larger than that of the latter. Among the moderators, the effect of type of soil (or growth media) and crop on the scale of modification of root system traits to K deprivation are stronger compared to the effect of type of K fertilizer applied. It is concluded that, overall, K deprivation leads to significant reductions in root system traits, especially root biomass and length in soils and perlite regardless of the type of K fertilizer applied. Attention should be given to K management in cropping systems to avoid K starvation, especially at the early and vegetative stages, and to improve K reserves in soils. Further attention should be given to the responses of root system traits to K supply when matching crops to soils

Pesticide Use Culture among Food Crop Farmers: Implications for Subtle Exposure and Management in Barbados

Globally, there is a strong interest in on-farm pesticide use culture due to genuine concerns about the individual, public, and ecological health risks posed by pesticides. At farm scale, pesticide use culture can be captured via the assessments of knowledge, attitudes, and practices (KAP) to inform intervention strategy and integrated science-based management. Despite the intensive use of pesticides in agriculture in the Caribbean, there is limited information on pesticide use culture or KAP assessment. This study assessed the pesticide use culture among selected food crop farmers in Barbados. A cross-sectional study of 93 food crop farmers, using a semi-structured instrument, was carried out. The results show that the respondents self-rated their level of knowledge on pesticide handling and application as medium to high but low on waste management. Over 50% of the respondents indicated they determine application rates and could understand and follow information on pesticide labels. The majority of the respondents relied on the Internet for information on pesticides, and less than half had received formal training on pesticide use in the three years preceding this study. On attitude, there was overwhelming support for the encouragement of pesticide usage to reduce losses in yield and quality of harvest. Knowledge did not always imply positive attitudes toward safe practices. While 86% agreed that pesticides posed considerable risks to the personal health of users, 60% agreed that one did not need to have all the recommended personal protective equipment (PPE) before using a given pesticide. Due to gaps in the knowledge–attitude–practice continuum, some respondents applied pesticides when necessary, and there was low adherence to the use of recommended PPE when handling/applying pesticides or cleaning/repairing pesticide application equipment, and some respondents indicated a tendency to eat, drink, or smoke during or immediately after pesticide application. These suggest subtle exposure. It was concluded that the low use of recommended PPE, high reliance on the Internet for pesticide guidance, and, particularly, pesticide waste disposal practices require urgent attention from policy, regulatory, and practical levels to improve the pesticide use culture

Quantifying perceived landscape desirability in human settlements: the case of four communities in Cape Coast, Ghana

Through their natural, aesthetic and cultural attributes, landscapes serve a range of human needs. The perception and value placed on these attributes and services confer desirability on a given landscape. Landscape desirability refers to the extent of acceptability or preferability of the perceived state and functioning of a given landscape in relation to serving the landscape needs of its human inhabitants. This paper presents the idea of, and an approach for quantifying landscape desirability using four communities in Cape Coast, Ghana. A landscape desirability index was derived from four factors (attractivity, wellbeing, dignity, and eco-resilience) based on scores assigned by respondents to three sub-components of each of the four factors. The results show that all the communities scored their landscapes moderately on attractivity, wellbeing, dignity, and eco-resilience, as well as overall landscape desirability. Bare surfaces and contribution to flood and  erosion mitigation were a major consideration in respondents’ scores of the sub-components of the factors. Nature and beauty (sub-components of attractivity) and sub-components of eco-resilience contributed considerably to the low desirability indices for the communities. This suggests the need to focus on these components in efforts to enhance landscape desirability. The findings suggest a need for wider studies to capture residents’ perceptions of their landscapes as an input into participatory landscape planning, transformation and management in Ghana. The quantitative approach applied can easily be adapted and replicated across communities and spatial scales to provide a comparable basis for sustainable landscape transformation in human settlements

The Gap between Theory and Practice of Stakeholder Participation : The Case of Management of The Korle Lagoon, Ghana

Participation of stakeholders at the local level is evolving as a mechanism to address complex environmental problems, not least water pollution. Participation has been used as a tool for the economic and social empowerment of settlements within the catchment of the Korle lagoon in Ghana, particularly residents of the Old Fadama community that live in proximity to the lagoon. Using direct observations and survey of stakeholder groups, the paper examines the structure and process of participation of stakeholders in Korle lagoon resource use and water policy formulation and implementation with regard to Korle Lagoon Ecological Restoration Project (KLERP). The results show that exclusion of stakeholders generates conflict and antagonism which hinders the implementation of water resource policy. Alliances of stakeholders in the participatory process have served as pressure points compelling government to negotiate with civil society on behalf of the community. In theory, participation holds promise to address conflict, however in practice, a number of factors that feed into conflict characterise the process of participation in this case, such as ineffective information flow in the community, agency-structure dynamics, historical antecedents among the ethnic groups and low-levels of communication. These gaps jointly undermine the full participation of the Old Fadama community in lagoon management

Assessment of the Impacts of Climate Change on Some Hydrological Processes of The Densu River Basin, Ghana

Water resources are among the most sensitive sectors to climate change due to their direct relationship with climate variables. The current study used projected climate datasets under two Representative Concentration Pathways (RCPs), 4.5 and 8.5, from the Coupled Model Intercompersion Project Phase 5 (CMIP5), remote sensing and Soil and Water Assessment Tool (SWAT) to estimate the effect of projected climate change on some hydrological processes. We focus on rainfall, water yield, soil water storage and evapotranspiration in the Densu Rvier Basin (DRB) for the 2050s. After calibration and validation of the SWAT model, there was a strong correlation between the simulated and the observed stream discharge coefficient of determination (R2) of 0.84 and 0.77, and a Nash Sutcliffe Efficiency of 0.76 and 0.70 for calibration and validation, respectively. The results showed an annual mean increase of 2 ºC in temperature, 61% in evapotranspiration and 20.1 mm in rainfall amount by the 2050s compared to their baseline values. Even though the mean annual soil water storage increases by about 80 mm, water yield declines by about 23 mm by 2050s. This appears to be due to the disproportionate increase in evapotranspiration compared to increase in rainfall. In conclusion, the DRB is projected to experience an overall reduction in water yield